I have ten labels on a page. I want to make these invisible in a for loop on page load.
I have tried this (doesn't work):
for (int i = 0; i < 10; i++)
{
my_lbl+i.Visible = false;
}
Therefore, it should do:
my_lbl1.Visible = false;
my_lbl2.Visible = false;
my_lbl3.Visible = false;
my_lbl4.Visible = false;
etc...
Is there a way to do this?
Put all of the labels into a collection:
private List<Label> labels = new List<Label>{my_lbl1, my_lbl2, my_lbl3, my_lbl4};
Then you can iterate the whole collection:
foreach(var label in labels)
label.Visible = false;
Make a List of them;
List<Label> yourlabels = new List<Label>{my_lbl1, my_lbl2, my_lbl3...};
and use foreach loop making them visible.
foreach(var label in yourlabels)
{
label.Visible = false;
}
I don't know if there is a better way but this way seems logical to me.
Putting the labels in a collection (as the previous answers have suggested) is a great solution. You can also retrieve the controls by their name using FindControl method of the Page.
for (int i = 0; i < 10; i++)
{
this.FindControl("my_lbl" + i.ToString()).Visible = false;
}
I guess you can utillize Page's FindControl method:
for (int i = 0; i < 10; i++)
{
FindControl(string.Format("my_lbl{0}", i)).Visible = false;
}
But check the case if control is not found of course.
Or, you can put them into dictionary:
Dictionary<string, Label> nameOfDict = new Dictionary<string, Label>();
nameOfDict.Add("label1", label1);
nameOfDict.Add("label2", label2);
For...
nameOfDict ["label" + incrementator].visible = false;
Or, create them dynamically into an array of labels.
If you're sure that, let's say, you want to uncheck all checkboxes in a groupbox, you can do this, too:
foreach (var item in groupBox1.Controls)
{
if (item.GetType() == typeof(CheckBox))
{
((CheckBox)item).Checked = true;
}
}
with LINQ:
foreach (var item in groupBox1.Controls.Cast<object>().Where(item => item.GetType() == typeof(CheckBox)))
{
((CheckBox)item).Checked = true;
}
TypeOf; it makes the whole thing a lot easier. Note that this is only possible if there is a control whose children is exactly the Controls you need, if there are other labels you don't want to affect in the lowest parent that contains all of those you do want to affect, this isn't feasible.
groupBox1.Controls.OfType<Label>() rather than groupBox1.Controls.Cast<object>().Where(item => item.GetType() == typeof(Label)). It's a pretty obvious refactor given that you want to do exactly what it does, based on it's definition. And saying that you're putting all of the content in a group box doesn't change the fact that it may not be possible. It's not just about describing how; it's quite possible, even probable, that it can't be done in this specific case.